Mets manager Terry Collins was in the home-team dugout lamenting his team, which can’t seem to catch a break. This was about three hours before the Mets opened a three-game homestand against the Diamondbacks at Citi Field.

Collins had just finished another press conference in which he tried to present an optimistic front while discussing the temporary loss of another important player to injury. This time it is was rookie pitcher Steven Matz, who was placed on the disabled list with a partial tear of the lat muscle on his left side.

“I’m tired of getting phone calls with bad news,” Collins muttered in the dugout. “I’ve never seen anything like this.”

The one thing that raised Collins’ spirits was talking about his players, the ones who have to carry on in the midst of these confounding injuries that seem to destroy any chance for real momentum.

“They battle,” Collins said of his players. “Win or lose, they keep battling.”

They proved the manager right on Friday night, putting aside the disappointment of losing Matz, to beat the Diamondbacks 4-2.

We sometimes forget in this win-now environment that this is a young Mets team finding its way through the adversities of a 162-game season. You have to figure lessons learned today will make them hardened professionals tomorrow.

There was no white flag waving at Citi Field on Friday night. Instead, there were sizzling fastballs and freaky change-ups thrown by Noah Syndergaard, who allowed a first-inning run, but was brilliant afterwards, striking out a career-high 13 before leaving to a standing ovation in the eighth. There was first baseman Lucas Duda breaking a 0-for-13 slump with a crushing three-run homer that bounced off the casing of the apple in center field. And there was outfielder Michael Cuddyer following Duda over the wall to deliver back-to-back homers.

Yes, the Mets battled and Syndergaard reminded everyone Matz isn’t the only phenom on the roster.

“He’s growing up fast,” Collins said.

With the tough news about Matz and the All-Star Game approaching, the Mets didn’t need to be swept at home like they were against the Cubs. It doesn’t need to get ugly this early, even though there’s plenty of reason that it should.

General manager Sandy Alderson stepped forward earlier in the day to accept blame, if there is any, for allowing Matz to pitch against Dodgers Sunday after the rookie reported soreness following his spectacular debut against the Reds on June 28. The southpaw from Stony Brook pitched six scoreless innings against the Dodgers, making him 2-0 with a 1.32 ERA and 14 strikeouts in two starts. Now he won’t throw a baseball for three weeks.

Matz called the injury “a minor thing,” and vowed, “I will be back.” But the poor kid hasn’t been around here long enough to understand no injuries are minor when it comes to the Mets.

“Nobody has guaranteed to us it’s going to heal in three weeks,” Alderson admitted.

It would be easy to blame Alderson for this Matz mess. He made the decision not to get an MRI exam and pitch the rookie against the Dodgers, knowing there was discomfort in his side.

“If we got an MRI [exam] on every pitcher who ever had any sort of mild pain we’d probably be doing them on a daily or somewhat frequent basis,” Alderson said.

Yet there was enough concern for the trainers, doctors and Alderson to confer about the pitcher’s health prior to his start in Los Angeles.

“I made the decision to allow him to pitch against the Dodgers based on confirmation of how he felt as well as the consultation among the trainers and the doctors,” Alderson said. “We did say if he continued to experience discomfort, we’d have him examined in New York and that’s what happened.”

Thanks to Syndergaard and Duda the healthy Mets were able to fight through more bad news and make their manager proud again.